Method and press for manufacturing tubular blanks for making containers therefrom



July 30. 1968 o. BIGINELLI 3,394,578

METHOD AND PRESS FOR MANUFACTURING TUBULAR BLANKS FOR MAKING CONTAINERS THEREFROM Filed Oct. 19, 1965 5 Sheets-Sheet 1 0. B NELLI 3,394,578

' BULAR BLANKS July 30. 1968 IGI ANU CONTAIN FACTURING TU ERS THEREFROM METHOD AND PRESS FOR FOR MAKING 3 Sheets-Sheet 5 Filed Oct. 19, 1965 FIG. 6

FIG. 4

United States Patent 4 Claims. in. 72-254 ABSTRACT OF THE DISCLOSURE A method and press for making tubular blanks or elements from which containers are formed. The blanks are made from heated metallic blanks squeezed in a matrix cavity having a tubular extension of shorter length and lesser diameter than the principal tubular portion of the matrix. This tubular extension forms a zone in which the impurities in the billet gather during the making of individual blanks. When a ram piston applies squeezing pressure to the billet a tubular blank is formed having a tubular extension corresponding to the tubular extension of the matrix. The impurities in the billet are principally contained in this tubular extension and it is removed mechanically from the completed blank.

A first object of the invention is to produce metal tubular blanks or elements, obtained by squeezing a metal billet and, having great regularity of wall thickness and a homogeneous structure for standing up to high pressures.

Another object of the invention is to produce flasks or cases with a bottom whose bottom is made so as to eliminate metal impurities accumulated in the bottom mass during forming thereof.

Another object of the invention is to produce a press enabling the drawing of the bottom mass of a tubular element such as aflask or case.

Other objects and advantages will be revealed by the description and claims, as well as the attached drawings, in which:

FIGURE 1 is a partial sectional view showing a matrix fixed to a hydraulic press head and the press piston provided with a billet fitted on the needle of the latter.

FIGURE 2 shows the first stage of the process in which the piston partially penetrates into the matrix, the needle or pilot of the piston being guided,

FIGURE 3 shows the piston at the end of travel, the

article then being formed,

FIGURE '4 is a sectional view of the product extracted from the press for cutting oif the end part in which metal impurities are accumulated after forming thereof,

FIGURE 5 is a sectional view of a tubular element having a semi-spherical bottom machined or shaped in a sound part of the tubular element,

FIGURE 6 is a sectional view showing the terminal stages of machining or shaping of part of the bottom of a tubular element such as a flask.

According to the invention, the manufacturing process for making of tubular elements consists of squeezing of a metallic billet comprising drawing the bottom mass of the tubular element formed from the billet so as to form an external extension to the squeezed or extruded walls and bottom of the tubular element in which metal impurities will accumulate at the end of the forming operation.

A device for operating this process comprises, as shown in FIGURE 1, a needle piston 1 cooperating with a matrix 2 fixed on a hydraulic press head.

The piston has an appreciably semispherical frontal "ice surface 1 whereas the bottom of the matrix cavity has a profile appreciably identical to that of the piston.

At the bottom of the matrix cavity and coaxially to a channel or pilot hole 3 for guiding the needle or pilot 1 of the piston, a drawing chamber or tubular extension 4 is provided in which drawing impurities will accumulate in an extension of the tubular element.

In the first stage of the process, an annular billet 5 is placed at a suitable temperature on the pilot 1 of the press piston 1 and rests on the frontal surface 1 of the latter.

In a manufacturing stage shown in FIGURE 2, the piston, which has a principal cross section of lesser diameter than the cavity, is thrust into the matrix cavity the pilot 1 of the piston is guided or piloted by the channel or pilot hole 3, the squeezing of the billet itself can commence.

In the manufacturing stage shown in FIGURE 3, the piston 1 is in the end of its travel, it has penetrated into the billet 5 squeezing out the walls of the tubular element 5 and the mass 5 of the bottom part of the tubular element.

The bottom of the cylindrical element has an appreciably semispherical profile, impurities are gathered or accumulated in the semispheric portion adjacent to the bottom of the matrix and more particularly in the extension 5 filling the tubular extension 4 of the matrix.

The tubular element once extracted from the press after the squeezing operation has the extension 5 cut-01f, in which the impurities are accumulated.

The bottom mass 5 has a perfect homogeneity and can undergo machining or shaping operations for imparting the bottom of the tubular element that has been formed, with the required profile.

In the form of embodiment shown in FIGURE 5, the bottom part of the tubular element 5, has undergone a supplementary operation for forming an annular seating 6 for the terminated tubular element.

Because of the present process, the bottom part 5 has a strength identical with that of the walls of the tubular element or blank and can, without inconvenience, undergo high internal pressures.

This process is particularly well adapted to producing drawn extruded cups of light alloy.

The process of the invention also enables calibrated tubular elements to be made of any length.

To this end, the cup is extruded out at the end of the squeezing until the required thickness of the walls desired is obtained, then, after squeezing the bottom part is cut, thus enabling a perfectly calibrated tube to be obtained.

In the form of embodiment shown in FIGURE 6, when it is required to give to a tubular element or blank a particular profile, a side-block 7 is placed at the bottom of the matrix cavity cooperating with a profiled piston so as to terminate the forming of the bottom part of the tubular element, 5

The left half of FIGURE 6 shows the piston bearing on the mass 5 of the bottom part, the right half of FIG- URE 6 shows the bottom profile obtained after squeezing the bottom mass of the tubular element.

The present process, in the first elaboration stage, enables a cup of metal or other material having a semispherical profiled bottom and a homogeneous bottom mass substantially free from impurities, the cup also having an insignificant eccentricity of the walls. The cup or tubular blank thus obtained can be used for two purposes:

(a) The producing, for example, of high pressure flasks by a supplementary machining or shaping of the bottom part according to any kind of profile,

(b) The producing of calibrated tubes by cutting the bottom part.

Of course, the invention is not restricted to the examples of embodiment described and shown above, for which other methods and forms of embodiment can be provided without going outside of the scope of the invention for that purpose.

What I claim is:

1. A method of manufacturing a tubular blank for making a container therefrom and having one end open and an opposite end partially closed comprising, providing a metallic, annular billet, disposing the billet in a matrix cavity having a cylindrical portion having an open end and a converging portion converging toward an opposite end of the cavity, said cavity comprising a tubular extension as a continuation of said converging portion co axial with said cylindrical portion and of considerably lesser diameter and axial length than said cylindrical portion, said matrix having a pilot hole in communication with said tubular extension, squeezing the billet by applying pressure thereto while in said matrix cavity by inserting a piston in said cavity having a pilot received in said pilot hole and a major cross section of lesser diameter than said cavity cylindrical portion and developing relative movement between said matrix and said piston such that said piston applies pressure to said billet in a direction toward said converging portion, whereby said billet is squeezed in a space in said cavity between the piston and said converging portion and said tubular extension and squeezed outwardly of said cavity circumferentially of said piston, removing the cylindrical blank from said matrix cavity, and removing from said blank an annular extension thereof corresponding to a portion of said billet squeezed in said cylindrical extension thereby to squeeze into said extension impurities in and on said metallic billet.

2. A method according to claim 1, including before positioning said billet in said matrix cavity heating said billet to an extrusion temperature.

3. A press for manufacturing tubular blanks for mak- 4O ing containers therefrom and having one end open and an opposite end partially closed comprising, a matrix having a cavity having a cylindrical portion open at one end for receiving therein a heated annular billet and a converging portion converging toward an opposite end of the cavity, said cavity comprising a tubular extension as a continuation of said converging portion coaxial with said cylindrical portion and of considerably lesser diameter and axial length than said cylindrical portion, said matrix having a pilot hole in communication with said tubular extension, a piston insertable into said cavity for squeezing a heated billet in said cavity for making a tubular blank therefrom having an open end and an opposite end partially closed, said piston having a major cross section of lesser diameter than said cylindrical portion and a pilot insertable into said pilot hole, said pilot having an axial length greater than the axial length of an annular billet received in said matrix cavity, whereby when said piston is inserted into said cavity and advanced toward said converging portion of said cavity a metallic billet in said cavity is squeezed circumferentially of said piston and outwardly of said cavity cylindrical portion through said open end thereof and a tubular extension is formed on the blank made in said matrix, and the last mentioned tubular extension corresponding to said tur bular extension of said cavity and containing therein irnpurities in the billet squeezed in said matrix cavity.

4. A press according to claim 3, in which said piston comprises a converging leading end insertable into said matrix cavity, and said pilot extending axially from said leading end.

References Cited UNITED STATES PATENTS 847,635 3/1907 Astfalck 72254 3,080,650 3/1963 Jury 72255 FOREIGN PATENTS 432,703 7/1935 Great Britain.

CHARLES W. LANHAM, Primary Examiner.

K. C. DECKER, Assistant Examiner. 

